1. Field of the Application
The present application relates to an axial turbine engine fitted with a transmission. More precisely, the present application relates to a turbojet having a fan, a compressor, and an epicyclic train.
2. Description of Related Art
In order to modulate the rotation speed of the fan, a turbojet is provided with an epicyclic train. It allows the rotor of the low-pressure compressor to be decoupled from the fan, which eliminates technological constraints. The rotation speed of the fan is reduced relative to the compressor rotor, which is advantageous for turbine engines with a high dilution rate, combining a large fan and a compressor of reduced diameter. This technology becomes useful for high-speed compressors, the rotation speed of which is greater than 10,000 rpm or even 15,000 rpm.
The presence of an epicyclic reducing gear also allows certain rows of rotor blades to be made counter-rotating i.e. turning in opposite directions. This allows an increase in the compression rate of the compressor.
Document US 2010/0326050 A1 discloses an axial turbine engine with, from upstream to downstream, a fan, a low-pressure compressor, a high-pressure compressor, turbines linked to the compressors and to the fan. An epicyclic reducing gear connects the fan to the internal rotor of the low-pressure compressor, these units turning in opposite directions at different speeds because of the reduction rate. However such a turbine engine is particularly complex. It has a number of interfaces in motion relative to each other, which requires the same number of sealing joints or bearings in order to limit wear. This arrangement is heavy and bulky, production precision becomes difficult. This configuration requires the addition of bearings or roller bearings between certain moving parts.
Although great strides have been made in the area of turbine engines, many shortcomings remain.